1. Technical Field
The present invention relates to a reel wound with recording tape such as magnetic tape and a recording tape cartridge.
2. Related Art
As an external recording medium for a computer or the like, a recording tape cartridge formed by housing a reel wound with magnetic tape in a case is known, for example. The reel includes a hub forming an axial center portion and wound with the magnetic tape around its outer periphery and an upper flange and a lower flange extending radially outward from axial opposite ends of the hub, respectively.
Conventionally, there is a known recording tape cartridge formed by winding recording tape such as magnetic tape on a single reel and rotatably housing the reel in a case made of synthetic resin, the tape used as a data recording and playback medium for a computer or the like. At a tip end (free end) of this recording tape, a leader member such as a leader pin, a leader tape, and a leader block is provided. A pull-out means provided to a drive device pulls out the leader member from an opening of the recording tape cartridge to thereby wind the recording tape fixed to it around a winding reel of the drive device.
In such a reel of the recording tape cartridge, the recording tape is normally wound around an outer peripheral face of its hub. An upper flange and a lower flange are provided above and below the hub, respectively. With the upper and lower flanges, the recording tape is restricted in its vertical height position, held to enhance a roll appearance and to improve traveling stability, and moreover protected from excessive damage when the tape is not in use.
Meanwhile, in many cases, the hub is formed into a cylindrical shape which has a bottom and in which axial one side is opened and the other side is closed. The hub in such a cylindrical shape with the bottom is likely to be deformed on its open end side having lower strength due to winding pressure of the magnetic tape. If the hub is deformed in this manner, the flange provided on the open end side of the hub is deformed in such a direction as to come in contact with a widthwise end portion (edge) of the magnetic tape.
Therefore, a configuration for reinforcing the hub with a metal ring so as to prevent deformation of the hub is conceivable as in Japanese Patent Application Laid-open (JP-A) No. 2004-14022 and JP-A No. 2005-116163, for example. However, in covering an outer peripheral face of the metal ring with resin and integrating the metal ring and resin with each other by insert molding, fluid resin may flow into a minute gap (of several tens of microns) existing between the metal ring and a metal mold in molding to thereby produce a resin burr on an end face of the metal ring and the burr causes variations in heights of hubs in dimensions of products.